The main components of a drive train of a motor vehicle are a drive unit and a transmission. A transmission converts torque and rotational speeds and thus implements the traction force available in the drive unit. The present invention relates to a method for operating a drive train, which has at least one drive unit and an automatic transmission. In the context of the present invention, the term automatic transmission should be understood to be any transmission with automated gear change or automatic gear change.
A method is known from DE 102 02 520 A1, by means of which a starting rotational speed may be determined for a starting process, namely in such a way that a target starting rotational speed specified by characteristic curves during the starting process is modified on the basis of a parameter that reflects the actual acceleration of the motor vehicle.
There are situations in which starting the motor vehicle with a starting rotational speed that is determined with the methods known from prior art cannot be ensured, and therefore may result in the motor vehicle staying halted. This is, for example, a situation in which a motor vehicle has to overcome an undetectable obstacle, such as a curbstone. In such a situation, reliably starting the motor vehicle with the methods known from prior art cannot be ensured.
Although the driver of the motor vehicle recognizes the need for increasing the starting rotational speed, the driver has no influence on it. With the methods known from prior art, there is no possibility for the driver to influence the increase of the starting rotational speed individually.